The cold cathode lamp has many advantages, such as smaller lamp tubes, simpler structures, less temperature increase, higher brightness on the surface of the lamp, being easily manufactured in different shapes, and long lifespans. Due to such specific properties, it has been widely applied in many kinds of applications, such as the liquid crystal display, notebook, mobile phone, scanner, and backlight source product.
A cold cathode lamp is a tube having the mercury vapor and inert gas therein and the two ends thereof have electrodes. In addition, the inner wall of the cold cathode lamp is covered with the fluorescent substance. The principle of luminescence is some of the electrons in the tube will be activated and hit the electrodes, and the secondary electrons would be induced accordingly after a high voltage is supplied into the electrodes. When the activated electrons collide with the mercury atoms, the mercury atoms would be stimulated and the ultraviolet would be emitted therefrom. The ultraviolet will stimulate the fluorescent substance covered on the inner wall of the tube to perform the visible light with the relative color temperature. The color of visible light is based on the covered fluorescent substance.
The performance of the cold cathode lamp depends on the operating frequency and voltage. The properties of each cold cathode lamp are different, so that it is inconvenient to adjust the operating frequency of the cold cathode lamp in a manufacturing process of the backlight source product. The operating principles for the driving circuits of the cold cathode lamp is that a high voltage transformer is applied to produce a fixed voltage, and the operating frequency of the cold cathode lamp is determined by changing the capacitance or resistance. Hence, the effect of the driving circuits of the cold cathode lamp on adjusting the backlight source product in the production line is limited.
Therefore, if the cold cathode lamp could be proceeded with the continuous frequency scan and voltage scan first before being used, it would be possible to observe the vapor properties and the optical spectrum strengths of the cold cathode lamp on the spectrometer. In addition, the most economic and effective methods for determining the optimal conditions of the key electronic components in the driving circuit of the cold cathode lamp are also the objects of the present study.
As above, the present invention provides a detecting apparatus for a lamp so as to obtain the optimal operating frequency and voltage and adjust the lamp into the optimal condition for overcoming the disadvantages of the prior art described above.